<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="./OL_SDK/include-openlayers-local.js"></script>
    <script src="./libs/gaode.js"></script>
</head>

<body>
    <div id="map">
    </div>
    <script>
        var map = new ol.Map({
            target: "map",
            layers: [gaode],
            view: new ol.View({
                projection: 'EPSG:4326',
                center: [114.30, 30.50],
                zoom: 4
            })
        })
        /* canvas作为样式设置给feature */
        /* 设置空的图层 */
        const source = new ol.source.Vector({});
        const layer = new ol.layer.Vector({
            source
        })
        map.addLayer(layer);
        /* 设置canvas */
        /* 初始化canvas */
        let size = 100;
        let canvas = document.createElement("canvas");
        canvas.width = size;
        canvas.height = size;
        let radius = size / 4;
        /* 执行绘制 */
        let ctx = canvas.getContext("2d");
        ctx.beginPath();
        ctx.arc(size / 2, size / 2, radius, 0, Math.PI * 2);
        ctx.closePath();
        ctx.fillStyle = "#652e80";
        ctx.fill();
        /* 将canvas作为样式设置 */
        const style = new ol.style.Style({
            image: new ol.style.Icon({
                img: canvas,
                imgSize: [canvas.width, canvas.height]
            })
        })

        /* 设置要素 */
        var point = new ol.Feature({
            geometry: new ol.geom.Point([114.30, 30.50])
        })
        source.addFeature(point);
        layer.setStyle(style);
        
    </script>
</body>

</html>